This page contains video clips that illustrate how to read the tracks once found. It may never be a complete listing because it is not set up as a repository.
Concept Illustrated: True Track (Canine toe pad)
The idea: Demonstrate the creation of, and difference between apparent and true track, as the track is being made.
The “true track” (term from Tom Brown, Jr.) is the track created by all surfaces of the foot in contact with the ground, up until the bottom surface of the foot itself has stopped compressing. It does not include the portions of the track created by pressure against the wall.
Another definition: “…the track bottom respective to the substrate, which was in direct contact with the trackmaker’s foot (Gatesway, 2003).”: Falkingham, P.L. 2016. Glossary: “true track…” in P.L. Falkingham, D. Marty, and A. Richter (eds.), Dinosaur Tracks: The Next Steps. Indiana University Press, Bloomington, Indiana.
Both “true” and “apparent” track are subjective terms. The top outer most outline of the track (apparent track) is often used as a measurement of its dimensions. For a useful discussion of this issue read: Falkingham, P.L. 2016. Applying objective methods to subjective track outlines; chap. 4 in P.L. Falkingham, D. Marty, and A. Richter (eds.), Dinosaur Tracks: The Next Steps. Indiana University Press, Bloomington, Indiana.
This outline is created during a process that begins the moment the foot contacts the earth … Continues while weight is applied … During the expansion of the foot outwards against the track wall … And up until the last contact between foot and earth … Perhaps even a bit further. It often includes the top of the ridge of soil pushed out and away from the foot as it rolls down onto the ground.
This can be an inaccurate measurement because it measures the displacement of soil after the foot leaving the track has been distorted by weight and force. It gets worse … After the foot has fully landed there can still be movement of the soil away from the edges of the foot … And the foot is still deforming and displacing soil. Measured this way, the dimensions of the track will include some of those distortions. These can vary with every step and are unlikely to be consistent.
Using the true track for measuring tracks will be more consistent. Variations in track measurements collected with this method are still possible, but will be reduced.
Finding the true track, well there’s the rub, if for no other reason than it can be a very fine distinction.
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Concept Illustrated: Dust Compressions (Dull on Shiny by Canine Toe Pad)
The idea: Simulate lowering the body and head to look for tracks on a ‘clean’ floor.
Tracks are created every time there is an interaction between a foot and a surface, and a bit beyond that even.
This illustration is meant to demonstrate a track being left on a ‘clean’ surface covered by a thin layer of dust made of particles so small that you only see them when your eye is at the correct angle to catch the light reflecting off the surface.
There is another version of this where the foot leaves moisture and/or body oil … Think fingerprint.
Concept Illustrated: A Simple Tire Track and Direction of Travel
The idea: Tires leave tracks. However, without knowing which details to examine, it can be confusing to determine the direction that tire was traveling by examining only a section of the track.
In the clip inserted above the goal is to give the observer a chance to watch one of the most obvious parts of a tire track being formed, and a couple of hints about where to look to figure out which way it was traveling.
The following version has a little more detail…
Notes about reading tire tracks: Haven’t studied this but have observed a few things, variables one might consider.
“How nice! They drove back the same way and the two trails are so close!”
What differences can you see between the tracks left by a trailer and the vehicle pulling it? (Turns make this easy)
Can you find a nick that’s repeated? What is the distance between those two nicks a measure of?
What is the length of the tire’s footprint? Is there any place along that vehicle’s trail that might give you a quick estimate of this? Why would this measurement even matter?
How do changes in forward motion show up?
How does inflation pressure affect the track?
What are the differences between a tire track created while maintaining motion (forwards or backwards), and one created while coasting? (Hint: Trailers) Acceleration?
What effect do the angles (relative to direction of travel) of the front and rear-facing edges of each tread segment, have on the track being left as the tread is interacting with the substrate? And on the final track?
Do the treads on a tire interact with the substrate the same way as lugs on a Vibram shoe sole?
This is just speculation … If the pressure releases in the wave (watch the clip … wave forms below white arc ) are indicating force applied to maintain or alter motion, are there instances where they also indicate direction of travel?
What about weight?
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The links below will take you to the rest of the illustrations.
Page: Foot Movements …
Canine Claw Tip Leaves Track in Fine Sand